Field
Various embodiments relate to optical fibers such as, for example, optical fibers with large core dimensions and optical fibers that support single mode propagation, as well as devices and systems that use such fibers such as, for example, lasers, amplifiers, and laser based material processing systems.
Description of the Related Art
Single mode optical fibers provide a flexible delivery media for high quality optical beams. Conventional single mode fibers typically have a core diameter below 9 μm. However, the small core diameter of the conventional single mode fiber is not well suited for delivery of high power optical beams. High optical intensity beams propagating in these fibers can cause strong nonlinear effects such as self-phase modulation, Raman scattering, Brillouin scattering, etc. Self-phase modulation can lead to pulse distortion. Raman and Brillouin scattering can lead to significant power loss during transmission.
Recently, fiber lasers based on rare-earth ions and Raman effects have found advantages in many applications over their solid state counterparts and their power level has been improving. One limit to further scaling of output power from a single mode fiber laser or amplifier is nonlinearity. However, the upper limit may be extended with designs using a much larger core diameter.
There is a need for single mode optical fibers. It may also be desirable for the fibers to operate over a very large wavelength range. Ease of use and manufacturing are also considerations which may lead to increased use.